Field of the Invention
The present disclosure relates to an image forming unit that forms an image on a recording medium by using an electrophotographic image forming system such as a copier, a printer (an LED printer, a laser beam printer, and the like), a facsimile machine, or a word processor.
Description of the Related Art
In an electrophotographic image forming apparatus (hereinafter, merely referred to as an “image forming apparatus” as well), typically, a drum-type electrophotographic photoconductor, that is, a photosensitive drum, serving as an image bearing member is uniformly charged. Subsequently, an electrostatic latent image (an electrostatic image) is formed on the photosensitive drum by selectively exposing the charged photosensitive drum. Subsequently, the electrostatic latent image formed on the photosensitive drum is developed as a toner image with toner serving as the developer. Subsequently, the toner image formed on the photosensitive drum is transferred on a recording material such as a recording sheet or a plastic sheet and, further, heat and pressure is applied to the toner image transferred on the recording material so as to fix the toner image on the recording material and to perform image recording.
Japanese Patent Laid-Open No. 2015-28545 discloses a configuration in which a charge roller is pressed against a photosensitive drum with an urging member.
As in Japanese Patent Laid-Open No. 2015-28545, in a case in which bearing members of a roller that contacts the photosensitive member are held by guides of the frame in a movable manner, there is a case in which the guides of the frame and the receiving portions of the bearing member are provided with gaps to maintain slidability with the receiving portions. Since the bearing members are movable within the areas that the gaps allow, there is a possibility of the bearing members vibrating inside the areas that the gaps allow during image formation cause the roller to vibrate and, accordingly, bring about an adverse effect on an image.